Your whole financial life, modelled to the month.
Calcifir plans for the household, not the individual. Two careers, two accounts, two life expectancies — all woven into one plan, with monthly precision and decades of projection.
Free to start. Research-backed math. No financial advisor required.
Built for the way you actually plan
Calcifir isn't a calculator with a spouse field bolted on. The household is the unit.
Household-first
Plan with a partner from day one. Two ages, two careers, two account stacks, two Social Security claims — all stitched together with joint-life math.
Monthly precision
Retire in March, not just "age 55." Claim Social Security the month you turn 70. Pay off the mortgage on the exact date you set.
Walk through your future
Drag a timeline scrubber from today to age 90. Press play and watch your plan unfold year by year. Every chart updates live.
Stress-test everything
Historical backtest, Monte Carlo, Bengen, Trinity — pick your risk model. See your chance of success at the strategy you're actually following.
Modular by design
Accounts, real estate, debts, income, expenses, money flow — each lives in its own focused module. Edit one thing at a time.
Show our work
Every formula cites its source: Bengen 1994, Trinity 1998, Shiller, SSA. We don't ask you to trust us. We show our work.
How it works
From signup to first projection in under five minutes. Then a lifetime of refinement.
Tell us about your household
A short quiz captures the basics — you, your partner, current savings, income, expenses, retirement goals. Five minutes to your first projection.
See where you stand
An overview dashboard shows your net worth today, projected net worth at retirement and death, chance of fully funding your plan, and a financial wellness score.
Explore the what-ifs
Retire two years earlier. Move to a tax-free state. Do Roth conversions. The What-If module shows the impact in seconds without breaking your baseline.
Refine as life changes
Plan accuracy increases as you fill in details. Update accounts as you save, reduce debts as you pay them off, add real estate as you buy. Your plan stays current.
We show our work
Every number cites a source. Every assumption is explicit. No black boxes.
The foundational research on safe withdrawal rates. Calcifir implements it correctly and shows you when not to use it.
Real S&P 500 returns, bond yields, and CPI inflation since 1871. Backtests run on actual history, not generated noise.
Default sample count for parametric, bootstrap, block, and regime simulations. Use the right model for your question.
Fixed real, CAPE-dynamic, Guyton-Klinger, VPW, floor-ceiling, spending smile, and more — modeled on the published research.
Five minutes to your first plan
Sign up, answer the quiz, see your overview. From there it's yours to refine — for the next 50 years.
Build your plan